Abstract: Mysids are predominantly free living marine animals more abundant in comparatively shallow water. However, as early as 1879, Hilgendorf recorded Heteromysis harpix as an associate of hermit crabs inhabiting gaatropod shells. Nothing was known about the nature of this association until Clarke (1995) published very interesting observations on the association between H. actinae and the sea-animone Bartholomea annulata.Since then O.S Tatterasal (9162) reported H.harpta as an associate of hermit crabs of the genus Dardanus, H. gymnura from the arms of an aphiuoroid and H.zeylanica from a sponge.